I'm about to convert my T3 7 mag to 6.5 and saw that carbon six offers a prefit in 20". I want to make a shorty for our small tower stands on my property. Proof only offers a 22 and 24 prefit thus me looking at carbon 6. Plus its slightly cheaper getting prefit and no gunsmithing other than check with go/no go. So if anyone has kne, let me know how you like it and any pros / cons.